Attack PRO - Wireless Bluetooth Spaceship Battle

What better way to use peer to peer apps than by doing local gaming? A simple little retro arcade game that allows you to take on your opponent over Bluetooth. It only features head-to-head multiplayer, however, so you won't be playing this one by yourself.

iSamurai: Critical Strike!

While Attack PRO is a fun game, nothing really beats swinging swords. iSamurai allows you to wield your iPhone or iPod touch as you would a sword. You can duel with a friend locally over Wi-Fi or Bluetooth.

Tic-Tac-Touch: FS5 (FREE)

After getting exhausted by swinging your iPhone around it may be time to sit down and relax to a good game of tic-tac-toe. Peer-to-peer Tic-Tac-Toe over both wifi and bluetooth. The same company, FlipSide5, also makes Touch4 (Connect 4) that works over bluetooth and wifi.

F.A.S.T. -- Fleet Air Superiority Tactics!

After being nice to planes it might be fun to blow some up! Full 3D dogfighting using the accelerometer for flight controls. Includes peer to peer Bluetooth support in addition to WiFi. Description does NOT say the peer to peer is compatible with original iPhone or original iPod Touch.

Leaf Trombone: World Stage

Touch4: FS5

Before leaving your peers it wouldn't hurt to make time for this classic Connect 4 game. This iPhone incarnation of the classic Connect 4 game already supported multi-player games over WiFi, EDGE or 3G, but with the new 3.0 version you can also play games using only Bluetooth.